The overall goal of Core A is to provide training, tools, technologies and model systems that will enable the projects of the PPG to analyze the structure and function of key adhesive junctions of the cardiac myocyte and to investigate how defects in cardiac cell-cell and cell-extracellular matrix molecular complexes disrupt structural integrity, electrical, mechanical and signaling functions in isolated cardiac cells, tissues and whole hearts. In particular, Core A will provide expertise and techniques to (a) image and analyze myocardial and myocyte structures including intercalated discs, costameres and their components;and (b) characterize cardiac muscle electrical, mechanical and signaling functions in three types of experimental preparation: isolated murine cardiomyocytes;isolated mouse trabeculae and papillary muscles;and isolated perfused adult or neonatal mouse hearts. In addition, Core A will bring expertise in bioengineering and biophysics, biophotonics and microscopy to collaborate with all three projects and the other cores in the design and development of new preparations, techniques and assays for analyzing structure and biophysical function mouse heart cells and tissues.